Self opening or releasing thread-cutting die.



P. JUDGE.

SELF OPENING 0R RBLEASING THREAD CUTTING DIE.

APPLICATION FILED IEB.2, 1914.

1,105,565. Patented July 28,1914.

3 SHBETSnSHEBT 1.

E. JUDGE. SELF OPENING 0R RELEASING THREAD CUTTING DIE.

APPLICATION FILED FEB.2, 1914.

Patented July 28, 1914 3 SHEETS-SHEET 2.

W a n 6 W wmv/o0 76 3 ,M6 o 6 7 ww k M .J W S\\\\\ P. JUDGE.

SELF OPENING 0N RBLEASING THREAD CUTTING Dm.

APPLICATION FILED FBB.2, 1914. 1,105,565, Patented July 28, 1914.

3 SHEETS-SHEET 3.

FRANKLIN JUDGE, 0F GREENFIELD, MSSACHUSETTS OPENING OR BELEASXNG THREAD-CUTTING 1.3111.

Application filed yFebruary 2, 1914.

To all whom it may concern.'

Be it known that FRANKLIN JUDGE, a citizen of the United States, residing in the city of Greenfield, county of Franklin, and State of Massachusetts, have invented certain new and useful Improvements in Self Opening or Releasing Thread-Cutting Dies, of which the following is the specification.

This invention relates to a new and useful improvement in self-opening or releasing thread cutting dies.

The object of the invention is to provide a die-head that will automatically open at the termination of the operation of cutting a thread on a piece of work whereby the work may be withdrawn without contact with the dies. It is designed to be used in connection with turrentlathes, screw machines and the like.

The invention consists in general of a movable die-head in which the chasers or lands are pivotally mounted, a cylindrical sleeve slidable on the die-head and a hollow spindle or stem member in which the die head is slidably mounted, said spindle member being designed to be secured to the turret of a turret lathe or yscrew machine.

The invention will be fully described in the body of the specification, and particun larly pointed out in the claims.

The objects of the invention are attained by the mechanism illustrated in the accompanying drawings in which:

Figure 1 is an end view of the complete die-head. Fig. 2 is a longitudinal sectional view on the line 2 2 `of Fig. 1, looking in the direction of the arrow, and showing the locking means for holding the sleeve, the trip therefor, and the elastic connection between the die-head and holding spindle. Fig. 3 is a longitudinal sectional View on the line 3 -3 of Fig. 1, looking in the direction of the arrow, showing particularly the pivotal mounting for the dies or chasers in the diehead proper, also the spring actuated pins or pllingers which engage the ends of dies to exert an action to normall) hold them open. Fig. Il is a side elevational view of the complete device showing clearly the lever by means of which the pivotally-inounted dies are closed before cutting the threads on a piece of work, and, the adjustable stop by means of which the size of the thread to be l cut may be accurately varied, said stop serving also Ato actuate the s ring actuated latch Speicatinn of Letters ment,

to release its hold on t e catch. Fig. 5 is Patented J lily 2,8, 1914- Serial No. 816,033.

a transverse sectional view on the line 5 5 of Fig. 3 looking in the direction of the arrow and showing the pivotal mounting for the dies, the lever for closing the dies and the spring actuated latch. Fig. 6 is a View similar to Fig. 3 but showing'the die-inembersiopen after the thread has been cut. Figs. 7 -to 19 are for a modification. Fig. 7 is an end view of the device with the'die members closed. Fig. 8 is a side elevational view. Fig. 9 is a vertical sectional view on the line 2 2 of Fig. 7 lookingin the direction of the arrow and showing the diemembers closed. Fig. 10 is a sectional view on the line 10 10 of Fig. 7. 11 is a sectional view on the line 11 11 of Fig. 8 showing the locking pawl in position to retain the die-members closed.' Fig. 12 is a sectional View on the line 12 12'of Fig. 7 Fig. 13 is a detail view of the cam block. Fig. 14 is a view similar to Fig. 9 but showing the die-members open. Fig. 15 is a transverse sectional view on the line 15 15 of Fig. 9, and Fig. .16 is a view similar to F 1g. 11 showing the latch in a released position. Figs. 17, 18, and 19 are detail views of the releasing pawl,

Referring to the drawings in detail: 1 designates the die-holding lmember which 1s formed with an extension part 2 that is slidably mounted in a hollowstem member 3 that is formed with a cylindrical shaped portion 4 against which the die-,holding member is adapted to rrest or strike. The stem-member Sis designed to be rigidly secured in the turret of a turret lathe. vAxially formed in the head 1 is a recess 5 into which the work projects when being threaded. Radially arranged and opening into the recessed portion 5 are slots 6, fourbf which are showii, and in which `the thread forming dies 7 are pivotally mounted, the ivot for each die being shown at 8. ,In order to normally retain the dies in place on the pivots S and to hold them in the open osition shown in Figs, 1, 2, 3, and 4, a spring actuated pin 9 engages the inner end 10 of each die member 7 (see Fig. 3), this pin is mounted in an externally threaded cup 11 which is threaded into radially arranged openings 12 in the die-head, the spring 13 being located between the head of the pin and ythe bottom of the cup. By means of this construction the tension of the spring may be adjusted. y i

i4 designates a pair of guide-pins or studs which project from the head part 4 of the hollow stem 3 and enter openings in the head 1. whereby a rotary motion between the extension part 2 and the hollow stem 3 is prevented.

15 designates an extension spring between the head 1 and the hollow stem 3. The ends of this spring are attached to a pin in head 1 and stem 3 respectively. The purpose of this spring is to normally retain these two members in a retracted position.

Referring now to the means by which the dies or chasers 7 are moved and held in a closed position for cutting a thread on apiece of Work, 16 designates a cylindrical sleeve or casing member that is slidably mounted on the head or die holding member 1. This sleeve is formed with openings 17 to permit access to the externally threaded cupmembers 11 for the purpose of adjusting the same. Also formed in this sleeve member is a triangular shaped opening 18, the apex portion 19 of which serves as a bearing for the pin 20 that is formed integral with or secured to the lever or handle 21 by means of which the dies or thread cutting elements may be moved to a closed position, when rotated about its pivot pin 22 which is secured to the member 1.

23 designates a flat or milled surface on the cylindrical sleeve 16 against which the operating handle or lever 21 rests. Surrounding the pin 22 is a sleeve 24 which affords abearing for the pin 22. The triangular shaped opening 18 furnishes sufficient space to permit the sleeve 16 to reciprocate without engaging the part 25. It should be stated that the pin 20, which moves through an arc of a circle produces the reciprocation of the slee-ve 16 to close the die-member 7.

Refering now to the latch construction by means of which the sleeve 16 is held in an extended position to retain the dies in a closed position during the thread forming operations and to automatically release the dies from the work and allow them to open after the thread is completed, 26 is a latch.A (see Fig. 2), that is pivotally mounted in the sleeve 16 at 27. It is normally actuated inward to its holding position by means of the spring 28. Mounted in the die-holding head 1 is a longitudinally arranged pin 29, its inner end being threaded as shown at 30. and, engaging this threaded portion is a catch -member 31 having a shoulder 32 against which the latch 26 strikes or engages when the dies are closed and before the catch 26 is automatically released. Between a vshoulder 33 and the end 34 of the internally threaded catch-member 31 is located a compression spring 35, to take up any lost motion that may occur between the Parts. The rotation of the threaded pin 29 causes the internally threaded catch-member 31 to travel on this pin either forward or backward in the groove 36 in which the catch member 31 is located.

Coming now to the description by means of which the lat-ch 26 is operated to release its hold upon the catch-member 31 at the completion of the formation of the thread: 37 designates a post that is rigidly attached to the hollow stem member 3 by means of the screw threads 38. Rigidly attached to this post and extending parallel with the axis of the die-head 1 is a rod 39 that is threaded at its-outer end. 40 and 41 are two nuts on this threaded portion. The inside nut 40 is formed with an inclined end 42 which is designed to engage the end 43 of the latch 26 when it is required to release the slee-ve 16 and permit the springs 13 to open the dies 7 whereby the work may be withdrawn. Secured to the sleeve 16 is a guide-bracket 44 through which the threaded rod 39 passes. The dies or chasers 7 are made from a single piece of metal. as shown. Their outer ends are formed with an inclined surface 45 which engages a correspondingly shaped notched surface 46 in the inner surface and outer end portion of the sleeve 16. The engagement of these two in clined surfaces serves, when the sleeve 16 is moved forward. to cam the dies radially inward against the springs 13 and toward each other to cut a thread of the correct diameter. The inner edge. of each die is cut away as indicated at 47 to afford space for the work to enter the axially arranged recess 5. It will therefore be seen that each die element 7 comprises an enlarged head portion 48 and a shank portion that is located in and extends into the grooves 7 where the pivotsS are located.

The operation of the structure shown in Figs. 1 to 6 inclusive is as follows: The hollow stem 3 is to be considered as rigidly secured in the turret head or mandrel of the lathe. The piece of work on which a thread is to be cut is secured to and revolves with the chuck which is attached to the spindle inv the head stock of the lathe. The operator, by means of handle 21 moves the cylindrical sleeve 16 forward on the die-head 1. This operation cams, by means of the inclined surfaces 45 and 46 the dies 7 inward against the tension of the springs 13. When vthe dies have been moved inward by the cylindrical sleeve 16 the correct distance. it is automatically locked or held in place by means of the lat-ch 26 engaging the shoulder on adjustable catch 31, which as heretofore stated. is slidably mounted in the groove 36 (sec Fig. 1) of the die-head 1. The piece of work on which a thread is to be cut is now rotated. and the turret-head or mandrel is advanced toward the revolving work which enters the die-head cutting a thread thereon, and causing the turret to travel toward the head stock until it` engages a suitable stop on the ways. The continued rotation of the piece of work on which a thread has been cut automatically causes the dies to open as this operation results in moving the die-head relative to the lifted stcni 3 and causing the inclined end 42 to engage the end 43 of the latch 26, rotating this latch on its pivot 27 and freeing it from the shoulder B2 of the catch 31. Upon the releasing of the catch 26 from the latch 31 the springs 13 act` by means of the inclined surfaces and 46 to cam or move the cylindrical sleeve 16 rearward, thus automatically opening the die-meinbcrs 7 and permitting the threaded work to be withdrawn. It will be noticed, that by rotating the threaded rod 29 that the longitudinal position of the slidablc catch 31 may be varied. and. consequently the size of the thread that is to be cnt will be varied as occasion requires.

Referring to the construction shown in l `igs. 7 to 19 inclusive: 50 designates a hollow stein member that is designed to be secured in the turret or mandrel of a lathe as already mentioned in connection with the construction shown in Figs. 1 to 6. This member is formed with an integral flange portion 51 to which the forwardly projecting stems 52 are secured, as by a driving lit. rlhesc stems have attached to their forward ends the tension springs 55% which are located in the recesses 54 of the die-head 55. The springs are attached to the die-head b v means of the pins 56 as shown. This construction permits the diehead to move axially relative to the hollow stem 50. 56 is a forwardly extending hollow portion of the part 50 and on which the die-head is located. The rear portion 57 of the diehead is reduced in size and on this portion is placed the cam block 58. shown in detail in Fig. 13, having the spirally arranged grooves 59 to receive the rectangular shapedpins 60 secured inthe sleeve 61. Attached to this sleeve is a ring 62 by means of the screws .63. The sleeve and ring. therefore.

constitute in fact a single element. Mounted in this sleeve on the pivot 64 is a latch 65 which coperates with a pawl 66 of the tubular member 67 which is interiorllv threaded to receive the adjustingr screw 68 which extends through the die-head 57 and cam block and the annular flange 51. as

shown. VIt is retained in place by means of the screw 69 entering a groove in the head of the screw as shown. Secured iii the diehead 57 a plate 70 to afford a bearing for the outer end of the adjusting screw 68. The purpose of this screw is to move the pawl 66 forward and backward to vary the position in which the die-members are locked to determine the size o the thread to be cut. as will be fully described in the statement of operation. 71 designates a second sleeve encircling the die-head 57 and formed with radial openings 72 to permit access to the cup-shaped adjusting springs 11, the construction and purpose of which have already been described in connection with the views shown in Figs. 1 to 6. The rear edges of this second sleeve, 71 rests against the sleeve 6l. 73 designates a cylindrical sleeve l0- cated at the outer end portion of the diehead 57 and formed with inclined shaped grooves 74 against which correspondingly shaped surfaces on the die-members 75 engage. Located on and engaging the threaded portion 76 of the outer sleeve 73 is a graduated ring 77 which bears against the end 7 8 of the sleeve 71. The purpose of this graduated ring is to limit the axial movement of the second sleeve after the screw 68 has been adjusted to cut a thread of the correct size. This graduated ring is provided with a set screw 78 to lock the same after the correct adjustment has been obtained. Rigidly secured to the cain block 58 is a pin 7 5) which enters a recess 80 in the die-head member 57 for the purpose of securely retaining the two members in relative relation to each other. The die-members or chasers 75 are pivotally mounted in the die-head at 81, the inner ends of which are engaged by the spring actuated pins 82 to normally press the outer ends of the die-members outward when the latch is released. The internally threaded catch-member 67 on which the pawl 66 is formed is provided with flattened sides 83 and 84 to prevent its revolving in the opening in the cam-block 58 (see Fig. 16). The latch 65 is normally pressed toward the pawl 66 by means of spring This latch is formed with a notched portion 86 to engage the edge 87 of the opening 88 in the cam-block in which the adjustable pawl 67 is located (see Fig. 11) which shows the cam-block locked. 89 is an operating handle that is secured to the sleeve 61 for the purpose ofI manually Closing the die-members 75 prior to the cutting of a thread on a piece of work. 90 designates a pair of screws for rigidly securing the camblock 58 to the die-head 57.

The operation of the self-opening die structure described in Figs. 7 to 19 inclusive is as follows: The hollow stem 50 is rigidly secured in the turret or mandrel of a lathe or screw cutting machine. The op erator closes the thread-cutting or die-members 75 by means of the handle 89 producing a rotary movement on the ring 61 b v means of this handle. The act of rotat ing the handle 89 causes the sleeves 71 and 73 to move axially on the head 55. This operation causcs the die-members 75 to be moved toward each other against the tenA sion of the springs in the cups 73 to the correct distance apart. The latch 55 during this operation is moved from the unlocked position shown in Fig. 16 to the locked position shown in Fig. 11. The diemembers are shown in their closed position in Figs. 7, 8, 9, 10, and 12, and in the open position in Fig, 14. To open the die-members after the thread has been cut on the piece of work the operator simply moves the turret head rearward a slight distance. This movement causes the inclined surface of the pawl 66 to cam the latch 65 so as to release its hold upon the cam-block 58 and when this operation takes place the springs in the cup-shaped boXes 73 acting through the inclined surface of die-members 75 against the inclined surface 74 of the sleeve 73 will cause the sleeves 73, ring 77, sleeves 71 and 61 to move rearwardly permitting the die-members 7 5 to open. Meanwhile the cam block 58 will, by means of the grooves cause the ring 61 and its latch 65 to assume the position shown in Fig. 16, it being understood that the cam-block is stationary, being secured to the part 50, by means of the screws 90 and held against rotary movement by means of the pin or stud 79. The object of making the camblock 58 with spiral or inclined grooves therein is to cause the latch 65 to be laterally moved away from the groove 88 and permit the sleeves 61, 71, 77 and 7?) to move rearward allowing the diemembers 75 to be opened. It will therefore be seen that I have produced a pull trip device for self-opening dies without requiring any attachment or harness of any kind whatever to be applied to the machine; being practically automatic in their action.

It is to be understood that I do not confine myself to the particular form ot cam-- block as illustrated in Fig. 13 as it is evident I may use any other suitable or equivalent structure that` will transmit an equivalent rotary and longitudinal movement to the cylindrical sleeve 61 in which the latch (i5 is pivotally mounted, lt is also evident that my device is not to be understood as limited to the use of a hollow spindle as it is evident that a solid one will accomplish the same results as the hollow one does.

lt should be stated that the compressionspring $15 serves the additional purpose of [n'eventing the adjusting-pin 25) from dropping out when unscrewed t'rom the catchmember 31. lt is clearly within the province ot' the skilled mechanic to rotatably rctain the pin '25) in place without the use otl the spring 235. It is also clearly within the province ot' my invention to substitute any equivalent modification for the screw-adjusting device ($8, as, `for example, the catch Gt', and screw 68 may, it desired. be formed in a single piece,

One ot' the particular advantages ot my invention is that it can be used with any ordinary lathe machine, screw-cutting machine, or milling machine without its being necessary to place any attachments or harness thereon to operate the die. Such attachments are generally cumbersome and oftentimes in the way of the workman thus lessening the amount or quantity of finished work he can turn out in a given length of time.

that I claim is 1. In an automatic die-head, the combination, of a member formed with an axially arranged recess and radial openings therein, die members pivotally mounted in said recess, means to normally move said members to an open position, a stem, a cam-device secured to the stem, a slidable ring, means on the ring to engage the cam-device to impart a rotary and longitudinal motion to the ring, pawl element, means to adjust said element, a latch carried by the ring to engage said pawl to retain the die-members in a closed position, a sleeve engaging said ring, a second sleeve, a second ring adjustable on the second sleeve to determine the position of the die-members with relation to each other, and means to position the pawl with relation to the latch.

Q. In a self-opening die. the combination, a die-head, die-members pivotally mounted thencin, said members having inclined outer edges,y a cylindrical sleeve to engage the inclined outer edges, the inner ends of the die-members having a recess to receive the pivots and inner extension portions, spring actuated devices mounted in the die-head to engage the extension portions of each diemember, a cam-device, a member having projections thereon to engage said cam-device, means to retain the die-members in a closed position, means to adjust the retaining means. and operative devices between the cylindrical sleeve and the member having projections thereon to cause the retaining means to operate to release the die-members when a pulling torce is transmitted to the die-head. as described.

3. In a self-opening die. the combination. ol" a die-head, die-members pivotally mounted therein, spring actuated plungers engaging the inner ends of said members, a cylindrical sleeve on the die-head to cam said members into a closed position, manual means to move said sleeve to close the members. a latch on the sleeve, a pawl with which the latch is adapted to engage, a threaded rod to adjust said pawl, a stem to secure the die-head to a suitable support, means operated from the sleeve to cause the unlocking ot the latch when a relative motion between the die-head and stem is produced, as described.

4. In a self-opening die, the combination, ot a recessed die-head. die-members pivotally mounted therein, means to normally move said members into an open position, a cylindrical sleeve, a cam-device secured to :e die-head, a member having projections thereon to engage the canhdevice. a latch pivotally secured to the lasbmentioned meniber, a pavvl to retain the latch in its locking position, a device to operate the pavvl for adjusting the position of the die-members relative to each other, a stem to secure the device to a suitable support, whereby upon a relative movement between the die-head and the stem, the latch will be disengaged from the paWl and the member with its latch camnied to an inoperative position, as described.

5. In a self-opening die-device, the com bination, a recessed die-head, die-members mounted therein and their outer edges hav ing inclined surfaces, a stem to secure the die-head to a fixed support, a cylindrical sleeve or shell movably mounted on the dehead to cani said members into a closed position when the sleeve is moved outwardly thereon, means to move said sleeve on the (lie-l1ead, means to lock the sleeve in its forward position to retain the die-members in a closed position, means to effect the release ot the sleeve upon ay relative motion between the die-head and the stem being produced, a tension device to permit said relative motion, spring actuated devices to cooperate vvith the die-members to move the sleeve to its inoperative position and Open the members, and manually operated means to reset the sleeve and close the diememhers, as described.

FRANKLIN JUDGE. il'itnesses:

CHARLES N. S'roDDARD, PHlLIr H. BALL.

Copies of this patent may be obtained for ve cents each, by addressing the Commissioner of Patents, Washington, D. C. 

